This investigation is primarily concerned with determination of the effect of renal prostaglandins on the development of renal hypertension, methods of prostaglandin analysis, and cellular actions of prostaglandins which promote or accompany changes in vascular contractility. Chronic inhibition of renal prostaglandin synthesis will be employed in the first study to ascertain whether these compounds contribute to the development or attenuation of renal hypertension. The second project consists of development of high-speed liquid chromatography as a tool to facilitate analysis of prostaglandins and their metabolites. Interactions of prostaglandins and cyclic nucleotides which may be involved in the modulation of vascular resistance will be examined in the third study by alteration and measurement of vascular levels of these compounds.